Mixing machine



y 1.952 A. A. FURCZYK 2,603,558

MIXING MACHINE Filed June a, 1947 2 SHEETS-SHEET 1 INVENTOR ALFONS A.FURCVZYK BY I I a. ATTORNEY y 15, 1952 A. A. FURCZYK 2,603,558

MIXING MACHINE Filed June 6, 1947 2 SHEETS-SHEET 2 M g M ATTORNEYINVENTOR ALFONS A. FURCZYK Patented July 15, 1952 7 MIXING MACHINEAlfons A. Furczyk, Philadelphia,.Pa., assignor to Selas Corporation .ofAmerica, Rhiladelphia, Pa., a corporation of Pennsylvania Application Jline 6, 1947, Serial N'. 753,095

8 Claims. (01. 48-180) The general object oftthe present invention is toprovide-improved gasmixing apparatus. -More specifically. the 'object'ofthe invention is to provide a simple and relatively inexpensive, butefficient gas mixing machine for use in supplying at widely varyingrates a combustible mixture of air and gas under a pressure appreciablyabove atmospheric pressure. The inventionwas devised and is adaptedforuse in mixingmachine units of relatively small capacity suitable fordomestic use; and particularly foriuse in supplying a combustiblemixture to'the burners of kit-chengas ranges and water heaters,:as Wellas for" many industrial uses in which the heat (requirement of the gasburner apparatus is relatively small.

It has longbeen generally recognized that in the operation ofindustrial-gas burning apparatus having relatively large heatrequirements; substantial technical and economic advantages areobtainable by premixing the gas to be burned with combustion air to forma combustible mixture containing predetermined proportions of gas andair, and supplying the mixtureto' the gas burning apparatus under apressure considerably above the pressure of the atmosphere. So-calledgas mixing machines for forming such'combustible mixtures and supplyingthem under pressure to furnaces and other gas burning-apparatus havingrelatively large heat requirements, are now in extensive and successfuluse. In general, the

same kindof advantages are obtainable when a preformed combustiblemixture of air and gas is supplied under'pressure to "gas burningapparatus having a relatively small heat requirement as whenthe mixtureis supplied to apparatus having a relatively large heat requirement.Heretofore,

withim'proved simple, inexpensive and. practically eil'ective meansfor-varying. the air-gas ratio of the mixture. The capacity for suchratio adjustment-is necessary to adapt the -mi-xing unit for "use-with.fuel gases of. different compositions. and

Bz t. n. values;- Moreover,'indomestic use as in industrial"use;lamixture havingthe air gas ratio required. for complete. combustion" willbe desirable m someca'ses; while in otherfcasesmixtures containing more"or' lessiai'r thanis. required for complete combustion, are desirable.

. The various-features. of..noveltygwhich,characterize ;my inventionarepointed' out with.par-,

10 Figure 1' is a plan view of amixing internal arrangement of themixing unit; .1

ticularity in the claims annexed to and forming a part of thisspecification. Fora better understanding of the invention,,however, itsadvari .tages, and specific objects attained with its use, referenceshouldfbe had to the accompanying drawing and descriptive matter inwhich I have illustrated and described preferred embodiments of theinvention. 1

Of thedrawings:

Figure 21s aview. partly insection showing Figure 3 is a section'on theline 3-3 (of Fig.',2; Figure 4 is a section on the line 4 -43 of 2; andv Figures 5 and 6 are sections taken similarly to Figure 4 and eachillustrating a different modification' ofthe ratio controlling apparatusshown in Figure h I f i The desirable embodiment of the presentinvention illustrated in Figures 1 to 4 comprises a centrifugal fan orblower housing structure A formed with an impeller chamber B. Animpelleiip mounted in the chamber B comprises a discrlike body withimpeller vanesor ribs C at the side of the impeller facing .a centralinlet opening Din the front wall -b of the chamber B. At its peripherythe fan housing structure is formedwith I a circular collecting channelE'open at its inner edge to the impeller chamber B and havinga-tangentially extending outlet E. The latter isshown as. having :athreaded end e .for connection,,lto piping for conveying the mixturetothegas-burner orburners in which the mixture is to be burned. AS;shown, the impeller C is carried by the shaftF' of a driving motor Fhaving its "frame rigidlyrattached to the housingstructure A,andhavingia base portion F through whichthe mix-ingunit may be mountedon a suitable support. Asshown, a 'bearingGffor the shaft F isinterposedbetween the impeller C and the motor F.

I In the'particular form shownyair and gasgpass intothe impeller chamberB through the inlet opening D? from a chamber H. -The latter, as

having side walls l-I' connected to and extending away from said bottomwall, and; having airemovable front wall I,' detachably secured ,to, the

side'walls.H= as by-screws The-side wallsyI-I may be cast integrally.with the adjacent; side wall b, or maybe welded to thelatter, orthe boxH and impeller housing may be made of a suitable plastic material, asconditions makedesirable.-. As shown, airwand gasgpass'separately intothe chamber I-I through passages id and ig through the front wall. Asshown, said passages are the bores of tubular bosses IA and IG. Each ofsaid bosses comprises an inner end portion at the inner side, and anouter end portion at the outer side of the plate-like front wall I. Forthe major portion of its length, each of the passagesor'boresiidlandiz'g is of uniform cross-section, but as shown, the outerend portion of each passage is enlarged and internally threaded to forma threaded pipe receiving socket. As shown,

an air supply pipe J has a threaded endiportiorr in the socket formed inthe outer end. of. the

boss IA, and a gas supply pipe Kisrthr'eade'dinto; the socket in theouter end -portion of the boss IGJ As shown, the pipe J receives airfrom the outlet of an air filter M which hasdts inlet m open to theatmosphere, and the pipe Kreceives gas from the outlet of a gas governorN, which receives gasv under a pressure above the pressure pi'the atmospere thr u h. p ne om re holder or other 'unillustrated" source of fuel;gas.

Theigas'governor comprisesa pressure responsive meansgincluding apressure chanfloer connected'tothepipeJ by the'con'duit N and a valve'by a; tapered valve or obt'urator- G. The valve OGmay'b'e; andas-shownis, a cone approximately coaxialwith the passage z'g in alloperative positiojns off the valve. In allthrottling positions of thevalveotir'- its apex is within the passage-- ig andia variablethrottling action is obtained by adjusting the" valve in the generaldirectionof its'axis; v

Inflthe no flow; or full throttling-position of the valve" 0G; thelatterentends so far intothe pajssage iy that the-inner'end of saidpassage is closed hrthe engagement'ofthe innerend of the wail"surrounding sa-idi passage with the portion ofthaconical-valve havingthesamediameter as thepassage igi 'I-he valve-dG-is' mountedon-thelowerendof a valve supportingm'ember' P-'- which also supportsa taperedvalve -OA variahly' throttling the air passage ill; Since the mixtureformed ordinarily containss'uhstantial-ly? more sienna gas,- thediameterof thepassage id is useana considerably greater than thediameter of'the passa'ge io: The valve membersO-Pt and 'd 'extend intothe passages iw and ig, respecave-y; for'the same distances-flin alladjustments.

The purpose of the-valves- 065- and 0A is'to proportionally increase anddecrease thecrosssecticnalarea of the annular space between the V ihier'wallof eaclrofthe passagesandtheperipheral' edge of the sectionthrough i the correspond-- ingvalve' on the plane' of" th'eirineredg'eof the hessesih and IG, inall adjustments of 'theivalves. r0 thi's en'd;the valve 0A is in theform' of a cone having'a'coni'caI angle suitablydifferent from that of the val ve 06 so: that the cross se'ctionalareas-- of'the said annularspaees may remain: in constant-proportion to-on'e another as the member ff-"moves-tl'ie val ves' fi'om theirwideopen posit'ibrr'in which the valves are wholly outside of passages m alldill, and: their fully closed positions" 7 positions;.

in which the inner end of each passage is filled by a base portion ofthe corresponding valve.

As shown, the valve supporting member P is in the form of a verticallydisposed skeletonized, or grid-like link having lower end portions P towhich the valves OA and 0G are connected and having spaced apartupperend portions B pivoted on aligned: horizontal pivot pins; mountedin brackets I carried by the removable front wall of the chamber H. Inthe closed positions of the valves, the center of gravity of the link Pand-the valves supported by it, is to the right of the vertical planeincluding the axes of the pivots I asseeninFigure; 2. In consequence,the valves areati allxtimes'subjected to a gravitational bias forcetending to hold the valves in their closed Whenthe fan is drawing airand gas out of.the chamber H through the port D, the fluid streamsflowing into the chamber H through the passagesza and ig, subject thevalve members to a differential pressure actionwhioh'diminishe's asthelengths ofithe. valve portions in the-passages are diminished; Withany. "given: rate" of flow 'through the' chamber I-I, the-valves come:toi'rest in the position in which the pressure'diffierential actiononthe" valves due to: the streamsof! air and-gas entering the chamber-H,equals thegr'avitationar bias force tending to; move the valvesin theirclosed positions. I

When the-valve memberszOA and 0G are in their fully closed positions,they are coaxial with the passages id; and ig, respectively-,5 enteredby the valves As the supporting memberrB'turns counter clockwise; as;seen in; Figure 2 tow-give. an opening 'movement torthe valves; the"axes, of the valves; are-similarlyturned outwoff alignment with theaxes: of: thepassages; id: and 19,. but, with: the parts proportionedgenerallyzass hown tha diver,- genceibetween. the: axis of each valve;and lt-he axis of'the: corresponding: passage is; slight, ancijof-v nopracticalconsequence. particularly as, said divergence diminishes asthethrottli ng effect of. the

val.v.e:isincreased. i Y

As shown: inzEigure 2,; the valve member'- OA; is providedzwithastenrextending throughzthecorrfispending-Jink portion Ri and anchoredin place byra' nut, O on: a: threaded end"; portionof the stem.ThevalveOG may, be similarlyconnected to the; link. P. When itbecomes.necessary to change the ratio of gas to air in the-mix-ture produced asin adapting-the mixture for use with different fuel gases having:different combustion air requirements, asto-towngas: and natural: gas,for example, the relative flow capacities of the passagesxia'andiiarmust; be varied:.. Such. variation can be: effected in variousways... For example, as illustrated in Figure. 5, thepassageza maythenhave its effective internal. diameter reduced'byza tubular liner Qexternally threaded. for screw thread engagement with an: internallythreaded portion of the passage in: When theadiameter of the airpassage: is, thus. reduced; the valve 0A shownin fiigurez-is replaced bya valveOA' having: acorresponding smaller conical angle to'main tain'thesame air togasrratio with the v'al ves tOG andQA' in their differentthrottlingpositionsr The air to gas: ratio'm'aintained. apparatusofi'the general character shown in; Figures 4, may

- be: reduced: without: the: use of theliner Q shown in. Figure 5 bysubstituting a valve, 0A. of the character shown; in Figure 6; for: the?valve OA shown in Figure 4.. r'lhetvalve 0A comprisega tapered portionof the: same efiective or'stream varying length as the-valves 0G, OA'and OA', and an axial: cylindrical 'eXtension"0A- at the aroma wi hadvantage-with at a H vs a P. th s l, en isalmn h usm'eSt HQ H E it i iwh pair f fcharnbers 1 including an impeller chamber and a i let .chamheia we n. t m e h r port ope i g, i t! Isaid impeller chamber fromsaidinle'tchamber, and with an inlet fchamber Wall'havin'g se arate sideby s' ir i ndieasimet passage extending throughfit, rotary impeller,in'i' aid impeller .ch'arnbehi a valve structureifor cross-sectionalarea of the valve G increases as the distancefromthe apex end ofthatvalve 7 increases. This means that the tapered portion of the valve0A is not a conebut is'a' conoidal body, the j'surfaceelements of whichare inclined to the axis of said body at an angle which in.crea'sesslightly as the distance from the junction of; the tapered andcylindrical portionsf of the v ire-incre ses? .i

l cram stiirdyf'compact units o'f; R e which canbemanufactiired at'a'relatively low cost. Such units may well have mixture output ing theirapex gm received fi 6 capacities varying from about one hundred cubicpassages feet per hour to one thousand cubic feet per 3' Apparatus as peified i l i 1, i hi h hour Uhits having h capacities are economi' saidvalves are in form of tapered obturators C y efiiclent for uses In WhiQht e amount of having their apex ends normally received in said mixtureused is too small to Justify the use of openings and having their 1-,i 1areas the lar and 11mm costly gas mixing machines varying along theirlengths so as to maintain a Which heretofore have b the only equallyconstant proportion between the minimum efficient devices available forsupplying combuscross seetiona,l area of th flow paths in the tiblemixtures under pressure and with an airtwo passages.

gas ratio remaining constant with wide variations Apparatus as specifiedin claim 1, inchldin mixture Output. The invention may also be ing anelectric motor having a rotor connected used in units having capacitiessubstantially to and rotating id impeller d m to frame greater than onethousand cubic feet D hour, mechanically connected to said fan housingas well as in units having mixture capacities of t t less than onehundred cubic feet per hour. 5 Apparatus as specified in l i 1, i 1 TVarying imlination the aXeS 0f the g ing an electric motor having arotor connected valves 0A, 0A and 0A" and 0G, to the axes of to androtating said impeller and a motor frame t e fl w passages ill and s] iWhich the Valves mechanically v connected to said fan housing areassociated, results in slight changes in the structure and Supporting ttt I form of he annular proportioning Orifice 6. In an air and gasmixing apparatus, a housion f h w p s hro h h p ges ia ing having amixing chamber provided with a and '9. e Orifice POrtion 0 fiow Pa iswall, said wall being provided with side by side the portion having thesmallest cross section i. e., ports for i d throttling va1v f r ea h einner end portion of the flow P through of said ports, a supportingmeans for said valves,

' the corresponding passage id or ig. Su h means to mount saidsupportingmeans on said Changes In the ol'lfice Shape are Without Practl wall forpivotal movement whereby said valves cal importance, however, becausethe changes in may be moved i t-, d t of id p t id shape of the twoorifices are small and similar, upporting means being shaped so that thegenand also because f e fact in normal Operation ter of gravity thereofisto one side of the mountthe mixture demand is usu y appmximately ingmeans so that it has a bias in a direction constant most of t e time, sa the Obtumtol to close said valves, and means to withdraw air valvesare held in nearly constant positions most and gas from said chamber tothereby cause said of the time. supporting means to move against itsbias to let While in accordance with the provisions of the air and gasflow into said chamber past said statutes, I have illustrated anddescribed the best valv s, forms of embodiment of my invention now 7.Air and gas mixing apparatus comprising known to me, it will be apparentto those skilled structure forming a chamber having a pair of in thatart that changes may be made in the walls, an inlet opening for air andan inlet opening forms of the apparatus disclosed without defor gaslocated side by side in one of said walls, parting from the spirit of myinvention as set a frame, a valve for each of said openings at-' forthin the appended claims, and that in some tached to said frame, means tomount said frame 14 to tree swinging mo ement ai structur ns rt-cham rsq at aid alv srmay emme into and out of restricting positionwithrespect to said openingssaid frame being shapedso. that thecenter ofgravity thereof is to one side of the mounting means so that it has abias 'to move said valves in a directionto close said openings, a portin the (other of said walls, and means mounted on said: structurete-withdraw as and airfrom saidchamber through said port tetherebyproduce a pressure drop across said valves wh reb d. ame and-valves wille. mov d a ainst t eir bias to. pe m t as and a r to fle 110- s hambe hru h the r resn ctiv a and'air inlet. op n n s- 7 -4 A r. and gas m x g.nnaratuscom r i a cent ifu al. fan ho s ng structure for e th an impel ec am er and with an inl tch ber and a rti ion. w l-bet een s chambersand iormedlwith an inlet port opening into said'impeller chamber fromsaid inlet chamber and with an inlet chamber wall having separateside-byide an as. inl p ssag s; t nd ng thr it, a rotary. impeller insaidimpeller chamber, a valvefitructure f or, simi larly throttling gasand air streams passing into said inlet chamber through said passagescomprising a separate throttling valve for each passage, a commonsupporting member for the valves, means to mount said valve structureforfree swinging movement, said valve structure being biased formovement of the valves ina direction which is opposite to the directionof the flow of said streams through said passages and which increasesthe throttling efiect of; said valveson said streamswhereby; said valvesare maintained inpositions displaced from bias tending to move saidbodies far enough into sai pa saae substantia y to e ntfiow he ethr h,

ALFO S U Q YK REFERENCES CITED The following references are of record inthe file; of this patent:

V UNITED STATES PATENTS N b r N me Date.

400,175 Bell Mar. 26, 1889 937,016 Wolff Oct. 12, 1909 ,050,6 GYe.,-.--.--.--.---+--, J n- 14, 1913 1,342,874v Session June 8, 19201,633,488 Graham" June 21, 1927 1,954,903, Walker V Apr. 17, i934 72,202,176 Timpson May 28. 1940 2 228,111, nth t eta? Jan, "1 194,1

1. AIR AND GAS MIXING APPARATUS COMPRISING A CENTRIFUGAL FAN HOUSINGSTRUCTURE FORMED WITH A PAIR OF CHAMBERS INCLUDING AN IMPELLER CHAMBERAND AN INLET CHAMBER AND A PARTITION WALL BETWEEN SAID CHAMBERS ANDFORMED WITH AN INLET PORT OPENING INTO SAID IMPELLER CHAMBER FROM SAIDINLET CHAMBER AND WITH AN INLET CHAMBER WALL HAIVNG SEPARATE SIDE BYSIDE AIR AND GAS INLET PASSAGES EXTENDING THROUGH IT, A ROTARY IMPELLERIN SAID IMPELLER CHAMBER, A VALVE STRUCTURE FOR SIMILARLY THROTTLING FASAND AIR STREAMS PASSING INTO SAID INLET CHAMBER THROUGH SAID PASSAGESCOMPRISING A SEPARATE THROTTLING VALVE FOR EACH PASSAGE AND A COMMONSUPPORTING MEMBER FOR THE VALVES, MEANS TO MOUNT SAID VALVE STRUCTUREFOR FREE SWINGING MOVEMENT AROUND A PIVOT, THE PIVOT FOR SAID VALVESTRUCTURE BEING TO ONE SIDE OF THE CENTER OF GRAVITY THEREOF SO THAT ITIS BIASED FOR MOVEMENT OF THE VALVES IN A DIRECTION WHICH IS OPPOSITE TOTHE DIRECTION OF FLOW OF SAID STREAMS THROUGH SAID PASSAGES TO INCREASETHE THROTTLING EFFECT OF TH EVALVES ON SAID STREAMS WHEREBY SAID VALVESARE MAINTAINED IN POSITIONS DISPLEACED FROM THE INLET PASSAGES BYAMOUNTS INCREASING WITH THE QUANTITY RATE OF FLUID FLOW THROUGH SAIDPASSAGES.